An operation checking method for an adaptive front lighting system (AFS), which is applicable to on-line automobile inspections involves an operation checking program prepared to activate the AFS in a manner to perform its prescribed headlamp illumination redirecting function and stored in advance in an in-vehicle ECU. While a finished vehicle remains stationary at an inspection zone of an automobile production and assembly line, the operation checking program is executed. During a run-time of the program, an inspection is performed to determine whether the headlamp illumination has been redirected by the AFS in leftward, rightward, downward and upward directions in a predetermined sequence as specified by the operation checking program.